OBJECTIVE: To identify risk factors and outcomes associated with a short umbilical cord. METHODS:We conducted a population- based case- control study using linked Washington State birth certificate- hospital discharge data for singleton live births from 1987 to 1998 to assess the association between maternal, pregnancy, delivery, and infant characteristics and short umbilical cord. Cases (n = 3,565) were infants diagnosed with a short umbilical cord. Controls (n = 14,260) were randomly selected from among births without a diagnosis of short umbilical cord. RESULTS: Case mothers were less likely to be overweight (body mass index 25 or more, odds ratio 0.7; 95% confi- dence interval 0.6, 0.8) and more likely to be primiparous (OR 1.4; 95% CI 1.3, 1.6). Case infants were more likely to be female (OR 1.3; 95% CI 1.2, 1.4), have a congenitalmalformation (OR1.6; 95% CI 1.4, 1.8), and be small for their gestational age (risk ratio 1.6; 95% CI 1.4, 1.9). A short cord was associated with increased risk for maternal labor and delivery complications, including retained placenta (RR 1.6; 95% CI 1.2, 2.3) and operative vaginal delivery (RR 1.4; 95% CI 1.3, 1.5). Adverse fetal and infant outcomes in cases included fetal distress (RR 1.8; 95% CI 1.6, 2.1) and death within the first year of life among term infants (RR 2.4; 95% CI 1.2, 4.6). CONCLUSION: Modifiable risk factors associated with the development of a short cord were not identified. Case mothers and infants are more likely to experience labor and delivery complications. Term case infants had a 2- fold increased risk of death, which suggests closer postpartum monitoring of these infants. OBJECTIVE: To identify risk factors and outcomes associated with a short umbilical cord. METHODS: We conducted a population-based case-control study using linked Washington State birth certificate-hospital discharge data for singleton live births from 1987 to 1998 to assess the association between Controls (n = 14,260) were randomly selected from among births without a diagnosis of short umbilical cord. RESULTS (n = 3,565) were infants diagnosed with short umbilical cord. : Case mothers were less likely to be overweight (body mass index 25 or more, odds ratio 0.7; 95% confi- dence interval 0.6, 0.8) and more likely to be primiparous (OR 1.4; 95% CI 1.3, 1.6) infants were more likely to be female (OR 1.3; 95% CI 1.2, 1.4), have a congenital malformation (OR 1.6; 95% CI 1.4, 1.8), and be small for their gestational age 1.4, 1.9). A short cord was associated wi 95% CI 1.2, 2.3) and operative vaginal delivery (RR 1.4; 95% CI 1.3, 1.5). Adverse fetal and infant outcomes in cases included fetal distress (RR 1.8; 95% CI 1.6, 2.1) and death within the first year of life among term infants (RR 2.4; 95% CI 1.2, 4.6). CONCLUSION: Modifiable risk factors associated with the development of a short cord were not identified Case mothers and infants are more likely to experience labor and delivery complications. Term case infants had a 2-fold increased risk of death, which suggests closer postpartum monitoring of these infants.